Recently, abuses associated with whole blood transfusion are becoming to be regarded as a serious problem, and component transfusion, whereby only the component parts of blood necessary for a patient are used for transfusion, is increasingly being adopted with a view to minimizing the physical burdens imposed on a patient and unfavorable side effects due to immunity and the like.
To make a component preparation, it is necessary to separate the component parts of blood in a blood bag by means of a centrifugal separator and to supply the component parts to respective separation bags.
In a conventional process, a separator stand such as that shown in FIG. 8 is used to manually separate centrifuged plasma in a blood bag and enclose the separated plasma by forming an enclosing portion in a tube extending from a separation bag.
That is, a blood bag 1 which has undergone centrifugation is set under vertically retaining pins 3 while blood corpuscles are prevented from rising. An intermediate portion of a tube extending from a separation bag 4 is previously closed by a clamp 6, and a separation needle 7 attached to the extreme end of the tube 5 is put through an outlet 1a of the blood bag 1 so that the two bags are connected with each other. A lever 8 of the separation stand 2 is then disengaged from a hook 9. The lever 8 that is constantly forced by a spring (not shown) in the desired direction thereby pinches the blood bag 1 between a swingable pressurizing plate 11 and a stationary plate 10 of the separation stand 2. At the same time, the clamp 6 closing the intermediate portion of the tube 5 is removed, thereby allowing plasma to be separately supplied to the separation bag 4. When blood corpuscles star entering the tube 5 after the plasma has moved to the separation bag 4, the tube 5 is closed by the clamp 6, the pressurizing plate 11 is returned, and the lever 8 is brought into engagement with the hook 9.
Thereafter, the separation bag 4 is pressed by hand and the clamp 6 is opened so as to discharge air toward the blood bag 1, and the tube 5 is closed by the clamp 6.
Conventionally, an ordinary separation process is based on manual operations, as described above, and entails the problems described below. 1) The burden imposed on the operator is considerable. That is to say, the separation operation is labor-intensive and is conducted one bag at a time. The number of bags simultaneously operated by one operator is at most two. The level of working efficiency is therefore low. 2) Such items of equipment as a separation stand, a balance and a tube sealer must be provided separately, and the space occupied by such equipment is considerable. 3) A high degree of skill and intuition are needed in controlling the quantity of each blood component part.